This application requests partial support for the 1995 INTERNATIONAL RESEARCH CONFERENCE ON NEUROFIBROMATOSIS, to be held in Philadelphia, PA, July 13-16, 1995. This is the thirteenth in a series of meetings since 1985 on the topic of neurofibromatosis. Previous meetings have been highly successful in attracting researchers from all around the world, representing a wide spectrum of basic science and clinical expertise, including molecular genetics, cell biology, clinical genetics, cancer biology, experimental therapeutics, drug discovery, gene therapy, etc. With the recent cloning of both the NF1 and NF2 disease genes, NF research has entered a particularly exciting new phase in which the normal and abnormal functions of both disease genes are systematically explored, thereby -- for the first time -- providing a rational basis for the possible development of mechanism-based therapeutic strategies. Similar to our successful 1994 FASEB conference on neurofibromatosis, the program for the 1995 INTERNATIONAL RESEARCH CONFERENCE ON NEUROFlBROMATOSlS will likely include seven platform sessions and an extended poster session, highlighting clinical updates, the molecular genetics, mutation analysis and diagnostic testing for both NF genes, as well as functional analyses of their protein products, neurofibromin and merlin/schwannomin. Particular emphasis will be given to newly emerging potential strategies for therapeutic interventions, such as anti-ras compounds. Time will be set aside for late breaking news. The successful extension and progression of this conference series from pure molecular genetic studies on the NF genes, to functional analyses of their protein products and their systematic utilization toward novel therapeutic avenues will also be reflected in the list of invited speakers and the overall program.